The invention relates to a rotating unbalanced weight vibrator. The vibrator has a vibrator housing lying on and defining an axis, and an electric motor positioned eccentrically in the vibrator housing relative to the axis. The electric motor includes a motor housing receiving a stator, a drive shaft extending lengthwise through the stator and being connected at one end to the vibrator housing with this end turning about the axis of the vibrator housing, and a rotor connected at the opposite end of the drive shaft and turning with the drive shaft.
Conventionally, the ends of the drive shaft are brought across the bearing bracket of the vibrator housing and are fixed in a swing bearing firmly positioned coaxially relative to the axis of the vibrator housing. Ring flanges of elastic material are arranged between the inner surface of the vibrator housing and the outer surface of the motor housing. These flanges brace the motor housing against the vibrator housing, and thereby prevent relative rotational movement between the vibrator housing and the motor housing. An aperture passes through the outer casing of the vibrator housing; an electric cable for supplying electricity to the coils of the stator is passed through this aperture.
This cable supplies the electric motor with alternating or three-phase current having a frequency of 50 Hz or more so that the drive shaft and rotor turn. As it turns, the rotor is also swinging like a pendulum, and this swinging movement is also imparted to the motor housing. The extent of this pendulum movement is determined by the behavior of the drive shaft extending from the vibrator housing. A disadvantage of the conventional embodiments is that the cable swings along with the motor housing; this is disadvantageous because the cable is rigidly connected externally of the vibrator housing to a supply network and the swinging movement alternately pulls and releases the cable in a back and forth movement. This bending movement exerted on the cable and the additional vibrations from the motor which are transmitted to the cable cause the cable to be subjected to a strong mechanical stress which leads to the breaking of the cable after a short time. Another disadvantage of this conventional design is that such a vibrator can only be used as an "outside vibrator" because of the positioning of the cable, and cannot be used as an "inside vibrator," so defined by its capacity to be directly inserted into thickening material.